Process for the production of a catalyst component for use in the polymerization of alpha olefins

ABSTRACT

The invention relates to a method for preparing a catalyst composition for polymerization of propylene, having high activity and producing polypropylene of high stereoregularity in narrow particle size distribution, which comprises: 
     1. reducing TiCl 4  by a mixture of diethylaluminum chloride (DEAC) and ethylaluminum dichloride (EADC), thereby forming a reduced solid (TiCl 3 ), 
     2. removing the aluminum compound from the reduced solid; 
     3. treating the said reduced solid with a mixture or complex of TiCl 4  and diisoamylether (IAE), and 
     4. separating the solid catalyst from the solution. 
     Preferably step 2 is performed by washing with a complexing agent for the aluminum compound.

FIELD OF THE INVENTION

This invention relates to an improvement in a catalyst component for usein the polymerization of α-olefins (which will hereinafter be referredto as "catalyst component") and more particularly, to a process for theproduction of a catalyst component capable of producing polymer having anarrow particle size distribution whereby in the stereoregularpolymerization of α-olefins such as propylene, in particular, not onlythe stereoregularity is improved but also the polymerization speed ismarkedly increased.

As a method of producing a crystalline polyolefin on a commercial scale,it has been widely known to use a polymerization catalyst comprising, incombination, a catalyst component consisting of a low valence transitionmetal halide, and an organo metal halide compound. In particular, atitanium trichloride composition has been used as the low valence metalhalide.

A known method of preparing a titanium trichloride composition consistsin reducing titanium tetrachloride by metallic aluminum at a hightemperature and then grinding the product for activation. The catalystcomponent prepared in this way is ordinarily called Grade AA titaniumtrichloride, which contains, in addition to titanium trichloride,aluminum chloride in an eutectic form, but has the disadvantage thatwhen used as a polymerization catalyst, the polymerization speed and thestereoregularity of the product are unsatisfactory and, on a commercialscale, a large amount of the expensive catalyst is necessary while agreat cost is simultaneously required for the treatment ofnon-crystalline polymer byproducts.

Many efforts have been made to overcome these disadvantages. Forexample, some of the catalytic components have been removed to improvesomewhat the polymerization speed or stereoregularity by extracting witha solvent (Soga et al. "Shokubai (Catalysts)" Vol. 11, page 75 (1969)),reacting with an ether compound followed by washing (Japanese PatentApplication (OPI) No. 34281/1973 or grinding together with variousmaterials followed by solvent extraction (Japanese Patent PublicationNo. 26376/1972). In these methods, however, the particle sizedistribution of the catalytic component has not been sufficientlyimproved, so that a polymer obtained using this catalyst component mayalso have a wide particle size distribution, resulting in trouble inhandling this polymer powder.

Another known method of preparing a titanium trichloride compositionconsists in reducing titanium tetrachloride with diethylaluminumchloride in a proportion substantially equimolar or less to the titaniumatom present at low temperature, as disclosed in, for example, JapanesePatent Publication Nos. 10415/1971, 21575/1972 and 11807/1972. Thismethod has the advantage that a catalytic component with a relativelyeven particle size can be obtained, but, on the other hand, the titaniumtrichloride composition obtained by this method is a brown β-typetitanium trichloride composition whose polymerization capacity is veryinferior. Therefore, it is necessary to subject this composition to aheat activation treatment to convert it into a violet titaniumtrichloride composition. In this case, however, the polymerization speedand stereoregularity when used as a polymerization catalyst are notsuperior to those in the case of using the above described Grade AAtitanium trichloride. The alkylaluminum dihalide byproduct of thereduction in the above-described method is regarded as a harmfulmaterial to the catalytic component and, as described in theabove-publications, for example, Japanese Patent Publication No.10415/1971, therefore, it is recommended to process it with a complexingagent such as ether compounds. Even if this processing is carried outwhen the reduced solid is subjected to a heating and activatingtreatment, the catalytic activity of the resulting component isdeficient.

As a further method of preparing a titanium trichloride composition, ithas been proposed to obtain a catalyst component capable of giving arelatively high polymerization speed, high stereoregularity andexcellent particle size distribution by reducing titanium tetrachlorideby diethylaluminum chloride at a low temperature to form a β-typetitanium trichloride composition and then treating it with a complexingagent and titanium tetrachloride to convert into a violet δ-typecatalyst solid, as disclosed in Japanese Patent Application (OPI) No.34478/1972 (published on Nov. 21, 1972). However, this method has thedisadvantage that when using a complexing agent other than diisoamylether, the titanium trichloride composition is not substantiallyimproved and further it is necessary to use a reagent having aconcentration of 15% by volume or more, preferably 30 to 40% by volumewhen treating titanium tetrachloride. Since diisoamyl ether is anexpensive reagent which is 10 to 20 times more expensive than otherorganic ether compounds or about 10 times more expensive than themarketed Grade AA titanium trichloride, the above-described method hasthe disadvantage that the production cost of the catalyst component on acommercial scale is high even though the product exhibits excellentproperties as a catalyst.

SUMMARY OF THE INVENTION

In accordance with the present invention, it has been found that acatalyst component having excellent catalytic properties can be obtainedby reducing titanium tetrachloride with dialkylaluminum monohalide and,in addition, alkylaluminum dihalide. Further processing results in acatalyst component having a largely improved polymerization activity andthe capability to produce polymer having high stereoregularity andnarrow particle size distribution.

Thus, the present invention provides a process for the production of acatalyst component for use in the polymerization of α-olefins, whichcomprises reacting titanium tetrachloride with a dialkylaluminummonohalide and monoalkylaluminum dihalide (said dialkylaluminummonohalide being in a proportion of equimolar or more to said titaniumtetrachloride) to thus obtain a violet reduced solid, then removingaluminum compounds contained in said reduced solid and furtheractivating with a complex consisting of diisoamyl ether and titaniumtetrachloride or a mixture of diisoamyl ether and titaniumtetrachloride.

Useful examples of the dialkylaluminum monohalide which can be used forthe reduction of titanium tetrachloride in the process of the inventionare dimethylaluminum chloride, diethylaluminum chloride, dibutylaluminumchloride, diethylaluminum bromide, diethylaluminum iodide and the like.Diethylaluminum chloride is preferable because it is readily obtainablecommercially and also excellent in processing capacity.

Useful examples of the monoalkylaluminum halide to be present togetherwith the dialkylaluminum monohalide in the process of the invention aremethylaluminum dichloride, ethylaluminum dichloride, butylaluminumdichloride, ethylaluminum dibromide and ethylaluminum diodide.Ethylaluminum dichloride is preferably used.

For purposes of illustration and not limitation, the present inventionwill now be described using ethylaluminum dichloride and diethylaluminumchloride in combination.

As described above, the method of reducing titanium tetrachloride bydiethylaluminum chloride is well known to those skilled in the art. Thisreaction can be represented by the following relations:

    TiCl.sub.4 + 0.5Et.sub.2 AlCl→TiCl.sub.3 + 0.5 AlCl.sub.3 + Et.

    TiCl.sub.4 + 1.0Et.sub.2 AlCl→TiCl.sub.3 + EtAlCl.sub.2 + Et.

As is apparent from these relations, the ratio of diethylaluminumchloride and titanium tetrachloride is ordinarily 0.5:1 to 1.0:1. It iswell known that the compound formed by this reaction, i.e.,ethylaluminum dichloride is a harmful material to the polymerizationreaction and, therefore, efforts have been made to remove it as far aspossible after the reducing reaction. However, the inventors have foundthat a violet reduced solid is obtained by reducing titaniumtetrachloride by diethylaluminum chloride in a proportion of 1 mol ormore to 1 mol of the titanium tetrachloride and ethylaluminum dichloridein a suitable amount, in particular, in a proportion of 0.3 to 1.2 molto 1 mol of the titanium tetrachlorde. This phenomenon is veryinteresting in view of the fact that only a brown reduced solid isobtained according to the prior art method, that is, in the case ofeffecting the reduction with diethylaluminum monochloride only withoutethylaluminum dichloride. X-ray diffraction spectra show that, in thecase of a brown reduced solid obtained by the prior art method, the peakof β-type crystal is considerably larger than the peak of Δ-typecrystal, while in the case of a violet reduced solid obtained accordingto the present invention, the peak of β-type crystal is very small orscarcely appears and the peak of α-type crystal appears strongly.

In the present invention, aluminum compounds contained in the violetreduced solid are removed and then the reduced solid is subjected to anactivation treatment using a complex consisting of diisoamyl ether andtitanium tetrachloride or a mixture of diisoamyl ether and titaniumtetrachloride. Even in the combination of the prior art method, that is,for removing aluminum compounds with a heating and activating treatment,the catalyst component obtained is not substantially improved, whileaccording to the present invention, a great advantage is obtained by theuse of a small amount of a complex consisting of diisoamyl ether andtitanium tetrachloride or a mixture of diisoamyl ether and titaniumtetrachloride.

It is another feature of the present invention that the method ofremoving aluminum compounds contained in the reduced solid is notlimited to treatment with a specific complexing agent, but that any ofseveral methods can effectively be used. The known method has hithertosucceeded in obtaining a relatively large improvement by the combinationof the method of removing aluminum compounds by treating with acomplexing agent followed by an activation treatment with titaniumtetrachloride, but, on the other hand, has the disadvantage that a largeimprovement cannot be obtained when another complexing agent thandiisoamyl ether is used. In fact, according to our tracing experiments,the improvement is very unsatisfactory even when the reduced solid istreated with, for example, di-n-butyl ether and then activated bytitanium tetrachloride only, as shown in the following ComparativeExamples.

According to the present invention, on the contrary, the removal ofaluminum compounds can be carried out not only by the use of a specificcompound such as diisoamyl ether but also by the application of theknown techniques, so long as the activation is carried out using acomplex or mixture of titanium tetrachloride and diisoamyl ether.

It is very difficult to explain why a complex or mixture of titaniumtetrachloride and diisoamyl ether has a particular action in the finalprocessing step of the catalyst component in the present invention, butit is true that there is a difference as to the object of usingdiisoamyl ether between the present invention and the above describedknown method, since the quantity of diisoamyl ether used in the formeris small while the quantity of diisoamyl ether used in the latter isvery large, that is, 0.8 to 1 mol per 1 mol of titanium. This ispossibly due to the fact that diisoamyl is used for the particularactivation action in the present invention, while diisoamyl ether isused for the purpose of removing aluminum compounds present in a largequantity in the known method.

A further feature of the invention consists in the quantity ofcomplexing agent and diisoamyl ether present in the finally processedsolid. This is to say, in the present invention, there remain in thefinal catalyst solid a considerable quantity of complexing agent anddiisoamyl ether even after the reduced solid is treated with thecomplexing agent to remove aluminum compounds, subjected to activationwith a complex or mixture of diisoamyl ether and titanium tetrachloride,washed several times with a fresh solvent and then dried. It is a wellknown fact in the art that if there are large amounts of such compoundsin the catalyst solid, the polymerization properties, and especially thestereoregularity of the product are markedly lowered and it is confirmedas shown in the following Comparative Example that the stereoregularityis markedly reduced if the polymerization is carried out with additionof a complexing agent corresponding, in variety and quantity, totitanium trichloride. Therefore, it is surprising that the catalystsolid of the present invention is capable of yielding a product having ahigh degree of stereoregularity in spite of the fact that it containslarge amounts of a complexing agent together with diisoamyl ether and itwill clearly be understood from this that diisoamyl ether used in thepresent invention is an essential condition for producing a catalystsolid capable of giving a polymer with a high degree ofstereoregularity.

The catalyst component produced by the process of the invention havingthe above described features is, excellent in activity and producespolymer having a low particle size distribution as is apparent fromExamples, and, furthermore, the process of the invention is economicalbecause diisoamyl ether is used in small quantities.

The reducing reaction of the invention is carried out by contactingtitanium tetrachloride with a reducing agent consisting of amonoalkylaluminum dihalide and dialkylaluminum monohalide, for example,ethylaluminum dichloride and diethylaluminum monochloride in an inertdiluent. In the present invention, in particular, the reducing agentused for the reduction of titanium tetrachloride is a mixture of diethylaluminum chloride in a quantity of equimolar or more to titaniumtetrachloride and ethylaluminum dichloride in a suitable quantity. Wherethe quantity of diethylaluminum chloride used is less than that ofequimolar to titanium tetrachloride, no favorable results are obtained.On the other hand, the quantity of ethylaluminum dichloride used ispreferably within a range of 0.3 to 1.2 mol per 1 mol of titaniumtetrachloride. As the inert diluent, C₄ l to C₁₂ aliphatic hydrocarbonssubstantially free of aromatic hydrocarbons or alicyclic hydrocarbons.The temperature of the reducing reaction is relatively important for theproperties of the final product and should be adjusted within a range of-50° to +30° C. The reaction is begun by contacting titaniumtetrachloride with the reducing agent while agitating the mixture,resulting in deposition of the reduced solid, insoluble in the inertdiluent. Contacting is carried out by adding dropwise either a solutionof titanium tetrachloride or a solution of reducing agent to the other.All the solutions are preferably agitated for 1 hour or more, inpartiular, 3 hours or more and during the same time, the reaction systemshould be kept at the above-described temperature. After both thesolutions are completely mixed, the mixture is kept at the sametemperature for at least 30 minutes, preferably 1 hour or more, thengradually heated and kept for 15 minutes or more at a constanttemperature between 20° and 120°, preferably 60° and b 100° C. withcontinuous agitation. The reduced solid obtained in this way should bethoroughly washed with a fresh solvent.

The aluminum compounds contained in the thus resulting reduced solid canbe removed by known techniques, for example, by subjecting the solid toa high vacuum to sublimate the aluminum compounds or by treating thereduced solid with a compound capable of forming a complex compound withthe aluminum compounds (i.e., complexing agent) and then extracting witha solvent. As the complexing agent (generally a Lewis base), there areused, for example, ethers, thioethers, thiols, organo phosphoruscompounds, organo nitrogen compounds, ketones or esters.

Examples of ether complexing agents are diethyl ether, diisopropylether, di-n-butyl ether, diisobutyl ether, diisoamyl ether,di-2-ethylhexyl ether, di-2-ethylheptyl ether, allyl ethyl ether, allylbutyl ether, anisole, phenetole, chloroanisole, bromoanisole anddimethoxybenzene.

Examples of the thioether complexing agents are diethyl thioether,di-n-propyl thioether, dicyclohexyl thioether, diphenyl thioether,ditolyl thioether, ethyl phenyl thioether, propyl phenyl thioether anddiallyl thioether.

Examples of the organo phosphorus complexing agents aretri-n-butylphosphine, triphenylphosphine, triethyl phosphite andtributyl phosphite. Examples of the organo nitrogen compounds arediethylamine, triethylamine, n-propylamine, di-n-propylamine,tri-n-propylamine and dimethylaniline.

Ethers, in particular, having 4 to 16 carbon atoms are preferably ascomplexing agents. The extraction can be carried out by any knownmethods, for example, by stirring the reduced solid with an ethercompound in an inert medium and separating into a liquid phase and solidphase. Such a medium may be the same as that used in the reducingreaction. The extraction is ordinarily carried out at a constanttemperature between 0° to 80° C, for 5 minutes or more, for example, 30minutes to 2 hours. The quantity of complexing agent used is ordinarily0.1 to 2.5 mols, preferably 0.4 to 1.0 mol per 1 mol of titanium atom inthe reduced solid.

The solid obtained by the above-described treatment is then subjected toan activation treatment with a complex consisting of diisoamyl ether andtitanium tetrachloride or a mixture of diisoamyl ether and titaniumtetrachloride. Preparation of such a complex consisting of diisoamylether and titanium tetrachloride can be carried out by contacting boththe compounds in equimolar amounts as it is or in a hydrocarbon solventat room temperature or with heating. This complex is a green platecrystal, complex compound of equimolar diisoamyl ether and titaniumtetrachloride, which can be confirmed by analysis after purification,for example, by recrystallization using a hydrocarbon solvent. In theactivation treatment with a complex according to the present invention,the thus prepared complex is used. The treatment of the solid with amixture of diisoamyl ether and titanium tetrachloride can be carried outby mixing the solid with diisoamyl ether and titanium tetrachloride, butit is preferable to mix both previously before use thereof. The quantityof diisoamyl ether used in the activation treatment should be 0.1 mol ormore per 1 mol of titanium trichloride in the solid whether the complexor mixture is used. If less than this range of ether is used, theresulting catalyst component is unsatisfactory in polymerizationacitivity and stereoregularity and if more is used, the particle sizedistribution of the catalyst component treated is broadened resulting inan increase of the proportion of fine powder in the product, in additionto poor economy, i.e. use of an excess of an expensive reagent.Therefore, in fact, the quantity of diisoamyl ether is preferably 0.1 to0.6 mol per 1 mol of titanium trichloride. On the other hand, thequantity of titanium tetrachloride is so adjusted that the concentrationthereof may be 1% by volume or more, preferably, 5% by volume or more ofthe whole liquid phase throughout the treatment. This activationtreatment is ordinarily carried out using a hydrocarbon solvent such aspentane, hexane, heptane, octane, cyclohexane or cyclopentane in such amanner that the solid concentration in the treating system be 50 to 800g/l, preferably, 200 to 600 g/l. The temperature of the activationtreatment is ordinarily within a range of -30° to 100° C., preferably40° to 80° C. and the time required for the activation is sufficiently30 minutes but should be 1 to 3 hours so as to obtain good results witha high reproducibility. Then the thus treated solid should thoroughly bewashed with the hydrocarbon solvent used in the above-describedtreatment.

The thus obtained catalyst component is used for the polymerizationtogether with a co-catalyst component. As the co-catalyst,organometallic compounds of Group I, II and III elements of the PeriodicTable are used. In particular, organic aluminum compounds are preferablyused and, above all, triethylaluminum and diethylaluminum chloride aremost suitable for the polymerization of propylene. Any polymerizationmethods known in the art can be used. For example, as an economicalmethod, a liquid monomer may be used as a polymerization medium withoutusing a polymerization diluent or a gaseous monomer may be usedsimilarly.

The present invention will be illustrated in detail by the followingExamples.

EXAMPLE 1

700 ml of purified heptane and 250 ml of titanium tetrachloride werecharged in a 2000 ml flask equipped with a stirrer and kept at 0° C. ina bath. 315 ml of diethylaluminum chloride (1.1 mol to 1 mol of titaniumtetrachloride) and 117 ml of ethylaluminum dichloride (0.5 mol to 1 molof titanium tetrachloride) were dissolved in 400 ml of heptane and addeddropwise from a dropping funnel. The dropping was continued for a periodof time of about 3 hours and, during the same time, the reaction systemwas kept at 0° C. After the dropwise addition, the reaction mixture wasgradually heated for 1 hour to 65° C. with agitation. The reaction wasfurther continued at the same temperature for another hour. Aftercompletion of the reaction, the reaction mixture was allowed to stand toseparate the solid formed and the solid was washed with 150 ml ofpurified heptane three times, followed by drying at 65° C. for 30minutes under reduced pressure. The thus reduced solid was red violetand, according to X-ray diffraction spectrum, the peaks of 2θ = 15.1°,33° and 51.3° (α-type crystal) were found but the peaks of 2θ = 16.3°and 42.4° (β-type crystal) were not found or very small if found. Theparticle size distribution of the product was very narrow and there was1% or less of particles of 5 microns or less. The molar ratio of Al/Tiin the reduced solid was 0.57.

150 g. of the reduced solid was suspended in 1850 ml of purifiedheptane, to which 127 ml (equimolar to the titanium in the reducedsolid) of di-n-butyl ether (referred hereinafter to as "NBE") wasdropwise added for 10 minutes with agitation at room temperature, andthe mixture was reacted at 35° C. for 1 hour. After the reaction, thereduced solid was washed three times with 500 ml of purified heptane toremove aluminum compounds contained therein, followed by drying at 65°C. for 30 minutes under reduced pressure.

30 g. of the solid, from which the aluminum compounds were substantiallyremoved by the above-described treatment, were resuspended in 53 ml. ofpurified heptane, to which 47.6 ml of a heptane solution of an equimolarcomplex of diisoamyl ether (referred hereinafter to as "IAE") andtitanium tetrachloride, adjusted previously to a concentration of 2mols/l, was added, and the mixture was reacted at 65° C. for 2 hours.The molar ratio of IAE to titanium trichloride was 0.6 and theproportion of titanium tetrachloride to the whole liquid phase was 10%by volume. After the reaction, the solid was washed three times with 100ml of purified heptane, followed by drying at 65° C. for 30 minutesunder reduced pressure.

The catalyst solid obtained in this way also had a narrow particle sizedistribution and there was only 2% of fine powder of 5 microns or less.Moreover, the catalyst solid contained NBE and IAE amounting to 0.09 moland 0.15 mol respectively per 1 mol of the titanium in spite of repeatedwashing and drying. The molar ratio of Al/Ti in the solid was 0.015.

100 mg of the catalyst solid was charged in an autoclave of 1000 ml, towhich 180 mg of diethylaluminum chloride as co-catalyst, 600 ml(Standard State) of hydrogen as a molecular weight regulator and 800 mlof liquid propylene were added. The polymerization was carried out at atemperature of 68° C. for 30 minutes and the unreacted propylene wasremoved by flashing, thus obtaining 193 g of polypropylene powder. Thusthe polymer yield per 1 g of the catalyst solid (catalyst efficiency,referred hereinafter to as "E") was 1930. This polymer had a melt flowrate of 4.5 (Melt Flow Rate -- ASTM D 1238-referred to as "MFR") and aheptane insoluble content of 97% (referred hereinafter to as "HI"),which was measured by extracting with heptane for 5 hours by means of aSoxhlet extractor.

The results are shown in Table I.

COMPARATIVE EXAMPLE 1

The procedure of Example 1 was repeated except that the activationtreatment with the complex consisting of titanium tetrachloride and IAEwas not carried out and the polymerization test was immediately carriedout, thus obtaining results as shown in Table I.

It is apparent from these results that the activation treatment with thecomplex is essential.

COMPARATIVE EXAMPLE 2

The procedure of Example 1 was repeated except that the activationtreatment with the complex consisting of titanium tetrachloride and IAEwas not carried out and instead a heating and activating treatment wascarried out at 150° C. for 1 hour, thus obtaining results shown in TableI.

It is apparent from these results that a marked improvement cannot beexpected by an activation treatment by heating even after removingaluminum compounds.

COMPARATIVE EXAMPLE 3

The procedure of Example 1 was repeated except that, in place of theactivation treatment with the complex consisting of titaniumtetrachloride and IAE, an activation treatment with titaniumtetrachloride having the same concentration was carried out, thusobtaining results shown in Table I.

It is apparent from these results that a marked improvement cannot beexpected by activating with titanium tetrachloride alone even afteraluminum compounds are removed and it is thus essential to add IAE atthe time of treatment with titanium tetrachloride.

                                      TABLE I                                     __________________________________________________________________________                 Example                                                                              Comparative Example                                                    1      1     2     3                                             __________________________________________________________________________    IAE/TiCl.sub.3 (Molar                                                                      0.6    --    --    --                                             Ratio)                                                                       Quantity of TiCl.sub.4                                                                     10     --    --    10                                             in whole                                                                     Liquid Phase (vol.%)                                                          Quantity of Ether                                                                          0.24   0.56  0.09  0.08                                           Remaining (Mol)                                                              Al/Ti (Molar Ratio)                                                                        0.015  0.08  0.07  0.014                                         Quantity of Particles                                                                      2      2     2     2                                              of 5 μ or less in                                                          Catalyst Solid (%)                                                             E          1930   720   420   1250                                            HI         97     55    93    96                                              MFR        4.5    10    3.9   4.9                                           __________________________________________________________________________

COMPARATIVE EXAMPLE 4

The procedure of Example 1 was repeated except that, in place of the NBEtreatment, a treatment with a mixture of 0.5 mol of NBE and 0.5 mol ofIAE per 1 mol of titanium trichloride was carried out to remove aluminumcompounds and then an activation treatment was carried out with asolution of titanium tetrachloride having the same concentration. Themolar ratio of Al/Ti in the resulting catalyst solid was 0.021. Thepolymerization results were E = 1270, HI = 95 and MFR = 6.0.

It is apparent from these results that the use of a small amount of IAEat the time of removing aluminum compounds is not so effective for theactivation and, that is to say, it is essential to use the same wheneffecting the activation by titanium tetrachloride.

COMPARATIVE EXAMPLES 5 AND 6

Using titanium trichloride of Grade AA manufactured by Toyo StaufferCo., a polymerization test was carried out (Comparative Example 5). Onthe other hand, another polymerization test was carried out withaddition of an ether compound in the same quantity as that remaining inthe catalyst solid obtained in Example 1 (Comparative Example 6).

The results are shown in Table II, from which it is evident that thecatalyst obtained by the present invention is very excellent inactivity, HI and particle size distribution and capable of givingexcellent properties in spite of that there remain a large quantity ofan ether compound in the catalyst solid. This is a very interestingphenomenon.

                  TABLE II                                                        ______________________________________                                                           Comparative Example                                                           5       6                                                  ______________________________________                                        Quantity of Ether Added (Mol)                                                                      --        0.24                                           Quantity of Particles of 5 μ                                                                    12        12                                             or less size in Catalyst Solid                                                (%)                                                                             E                  450       610                                              HI                 93        82                                               MFR                4.7       8.0                                            ______________________________________                                    

EXAMPLES 2 TO 4

The procedure of Example 1 was repeated except the quantity of theequimolar complex of IAE and titanium tetrachloride was varied, thusobtaining results as shown in Table III.

EXAMPLE 5

The procedure of Example 1 was repeated except that, in place of thecomplex consisting of titanium tetrachloride and IAE, titaniumtetrachloride and IAE were separately added to the processed solid toactivate it, thus obtaining results shown in Table III.

                                      TABLE III                                   __________________________________________________________________________                 EXAMPLE                                                                       2      3      4      5                                           __________________________________________________________________________    IAE/TiCl.sub.3 (Molar Ratio)                                                               0.1    0.3    2.4    0.6                                         Quantity of TiCl.sub.4 in                                                     Whole Liquid Phase                                                            (% by volume)                                                                              1.5    5      40     10                                          Quantity of Ether Re-                                                         maining (Mol)                                                                              0.28   0.25   0.20   0.28                                        Al/Ti (Molar Ratio)                                                                        0.018  0.025  0.10   0.13                                        Quantity of Particles                                                         of 5 μ or less size in                                                     Catalyst Solid (%)                                                                         1      1      8      3                                             E          1370   1550   2300   1800                                          HI         89     93     97     95                                            MFR        3.9    5.0    5.0    4.2                                         __________________________________________________________________________

EXAMPLES 6 TO 12

The procedure of Example 1 was repeated except that mixtures of IAE andtitanium tetrachloride in various proportions, previously prepared, wereused in place of the complex consisting of titanium tetrachloride andIAE, thus obtaining results as shown in Table IV.

                                      Table IV                                    __________________________________________________________________________                  Example                                                                       6      7      8      9      10     11     12                    __________________________________________________________________________    IAE/TiCl.sub.3 (Molar Ratio)                                                                0.1    0.3    1.0    0.1    0.3    0.6    1.0                   Quantity of TiCL.sub.4 in                                                                   10     10     10     40     40     40     40                    Whole Liquid Phase                                                            (% by volume)                                                                 Quantity of Ether                                                                           0.22   0.17   0.24   0.19   0.16   0.13   0.13                  Remaining (Mol)                                                               Al/Ti (Molar Ratio)                                                                         0.017  0.018  0.020  0.019  0.018  0.015  0.020                 Quantity of Particles                                                                       1      2      4      1      2      3      7                     of 5 μ or less size                                                        in catalyst solid (%)                                                           E           1620   2120   1760   1790   2250   2220   1980                    HI          97     97     97     97     98     98     95                      MFR         4.8    5.0    7.1    3.9    7.2    6.1    5.2                   __________________________________________________________________________

COMPARATIVE EXAMPLES 7 TO 9

The procedure of Comparative Example 3 was repeated except varying theconcentration of titanium tetrachloride in the whole liquid phase, thusobtaining results as shown in Table 5. It is apparent from these resultsthat the activation treatment using the complex of mixture of thepresent invention is very excellent.

                                      Table V                                     __________________________________________________________________________                 Comparative Examples                                                          7     8      3      9                                            __________________________________________________________________________    Quantity of TiCl.sub.4                                                                     1.5   5      10     40                                           in Whole Liquid Phase                                                         (% by Volume)                                                                 Quantity of NBE                                                                            0.12  0.11   0.08   0.06                                         Remaining (Mol)                                                               A1/Ti (Molar Ratio)                                                                        0.023 0.031  0.014  0.016                                        Quantity of Particles                                                                      1     1      2      2                                            of 5 μ or less size                                                        in Catalyst Solid (%)                                                           E          820   1050   1250   1340                                           HI         81    92     96     95                                             MFR        8.9   3.9    4.9    7.0                                          __________________________________________________________________________

COMPARATIVE EXAMPLES 10 TO 19

The procedure of Example 1 was repeated except effecting the reductionof titanium tetrachloride using diethylaluminum chloride only as areducing agent instead of the reducing agent consisting ofdiethylaluminum chloride and ethylaluminum dichloride and effecting theactivation treatment, after the NBE treatment, using a complexconsisting of IAE and titanium tetrachloride (Comparative Examples 10 to12), a mixture of IAE and titanium tetrachloride (Comparative Examples13 to 16) and titanium tetrachloride only (Comparative Examples 17 to19), thus obtaining results shown in Table VI. It will clearly beunderstood from these results that the joint use of ethylaluminumdichloride during the reducing reaction results in a remarkableimprovement of not only the catalytic activity but also the particlesize property of the catalyst.

                                      TABLE VI                                    __________________________________________________________________________                   COMPARATIVE EXAMPLE                                                           10  11  12   13   14   15   16   17   18   19                  __________________________________________________________________________    IAE/TiCl.sub.3 (Molar Ratio)                                                                 0.1 0.3 0.6  0.1  0.3  0.1  0.6  --   --   --                  Quantity of TiCl.sub.4 in                                                     Whole Liquid Phase (% by                                                                     1.5 5   10   10   10   40   40   1.5  10   40                  Volume)                                                                       Quantity of Ether Remain-                                                     ing (Mol)      0.17                                                                              0.24                                                                              0.2  0.20 0.23 0.15 0.18 0.11 0.08 0.05                Al/Ti (Molar Ratio)                                                                          0.018                                                                             0.025                                                                             0.017                                                                              0.021                                                                              0.019                                                                              0.015                                                                              0.012                                                                              0.022                                                                              0.018                                                                              0.015               Quantity of Particles of                                                      5 μ or less size in Whole                                                                 2   2   3    2    2    4    15   4    6    15                  Liquid Phase (%)                                                                E            1150                                                                              1280                                                                              1500 1270 1470 1310 1620 750  1050 1090                  HI           89  93  97   96   96   97   97   75   94   96                    MFR          3.9 5.0 5.1  4.8  5.0  3.9  5.9  7.8  3.0  6.1                 __________________________________________________________________________

EXAMPLES 13 TO 16

The procedure of Example 1 or Example 9 was repeated except varying thequantity of NBE used, thus obtaining results shown in Table VII. It isevident from these results that the effect of the quantity of NBEnecessary for removing aluminum compounds is not so large within theexamined range.

                                      TABLE VII                                   __________________________________________________________________________                  EXAMPLE                                                                       13     14     15     16                                         __________________________________________________________________________    NBE/TiCl.sub.3 (Molar Ratio)                                                                0.5    0.8    1.5    0.5                                        IAE/TiCl.sub.3 (Molar Ratio)                                                                0.6    0.6    0.6    0.3                                        Quantity of TiCl.sub.4 in                                                                   10     10     10     40                                         Whole Liquid Phase                                                            (% by volume)                                                                 Quantity of Ether Re-                                                                       0.25   0.24   0.26   0.15                                       maining (Mol)                                                                 Al/Ti (Molar Ratio)                                                                         0.018  0.017  0.015  0.015                                      Quantity of Particles                                                                       1      1      2      3                                          of 5 μ or less size in                                                     catalyst solid                                                                  E           1900   2050   1970   2180                                         HI          97     97     97     98                                           MFR         3.9    4.6    5.5    4.9                                        __________________________________________________________________________

EXAMPLE 17

The procedure of Example 1 was repeated except using IAE in an amountequimolar to titanium in the reduced solid instead of NBE used forremoving aluminum compounds in the reduced solid. Consequently, thequantity of particles of 5 microns or less in the catalyst solid was 2%,the quantity of ether remaining was 0.21 mol and Al/Ti ratio was 0.021(molar ratio). E = 1890, HI = 97 and MFR = 6.1

EXAMPLES 18 TO 20, COMPARATIVE EXAMPLES 20 TO 22

The procedure of Example 1 was repeated except using various complexingagents in an equimolar amount to titanium trichloride in place of NBEused for removing aluminum compounds, thus obtaining the results shownin Table VIII.

For comparison, the same complexing agents were used and thereafter anactiviation treatment with titanium tetrachloride only was carried outinstead of the activation treatment with the complex consisting oftitanium tetrachloride and IAE. The results are shown in Table VIII.

It is evident from these results that various compounds can be used forremoving aluminum compounds and it is essential to add IAE in thesubsequent activation treatment.

                                      Table VIII                                  __________________________________________________________________________                   Example             Comparative Example                                       18     19    20     20     21    22                            __________________________________________________________________________    Complexing Agent                                                                             Tributyl-                                                                            Ethyl Methyl Tributyl-                                                                            Ethyl Methyl                                       amine  Benzoate                                                                            Trichloro-                                                                           amine  Benzoate                                                                            Trichloro-                                                acetate             acetate                       IAE/TiCl.sub.3 (Molar Ratio)                                                                 0.6    0.6   0.6    --     --    --                            Quantity of TiCl.sub.4 in Whole                                                              10     10    10     10     10    10                            Liquid Phase (% by volume)                                                    Al/Ti (Molar Ratio)                                                                          0.018  0.021 0.39   0.028  0.029 0.051                         Quantity of Particles of                                                                     1      1     1      1      1     1                             5 μ or less size in                                                        Catalsyst Solid (%)                                                             E            1300   1080  1320   650    510   700                             HI           95     95    95     89     91    90                              MFR          3.5    4.8   3.9    7.9    7.1   7.7                           __________________________________________________________________________

COMPARATIVE EXAMPLES 23 TO 25

In Comparative Example 23, the procedure of Comparative Example 13 or 14was repeated except using IAE in an equimolar amount to Ti to removealuminum compounds instead of NBE and then using titanium tetrachloridein a quantity of 40% by volume for the activation.

In Comparative Example 24, the quantity of IAE used at that time wasdecreased to 0.5 mol to 1 mol of Ti.

In Comparative Example 25, the procedure of Comparative Example 23 wasrepeated except adding further IAE in a quantity of 0.3 mol to Ti at thetime of treating with titanium tetrachloride.

The results obtained are shown in Table IX.

                  Table IX                                                        ______________________________________                                                   Comparative Example                                                          23       24         25                                              ______________________________________                                        Al/Ti (Molar Ratio)                                                                       0.017      0.023      0.017                                       Quantity of Particles                                                                     7          4          6                                           of 5 μ or less size                                                        in Catalyst Solid (%)                                                           E         1680       860        1520                                          HI        97         95         97                                            MFR       4.9        3.8        5.3                                         ______________________________________                                    

It is apparent from these experimental results that the catalyst of thepresent invention has an activity similar to or same as the catalystsproduced by the known methods in spite of that the quantity of IAE usedis small in the former and the performance of the catalyst is markedlylowered if the quantity of IAE is decreased in the known method of theprior art. Moreover, it will be understood that there is no effect ofimprovement even if the procedure of the present invention is applied tothe known method.

What is claimed is:
 1. A process for the production of a catalystcomponent for use in polymerization of alpha-olefins whichcomprises:reducing titanium tetrachloride with a mixture of a dialkylaluminum halide with an alkyl aluminum dihalide, wherein said dialkylaluminum halide is employed in an amount of at least 1 mole per 1 moleof titanium tetrachloride and said alkyl aluminum dihalide is employedin an amount within the range of from 0.3 to 1.2 moles per 1 mole oftitanium tetrachloride, to obtain a violet titanium trichloride reducedsolid containing aluminum compounds; removing aluminum compounds fromsaid violet titanium trichloride reduced solid; and thereaftercontacting said violet titanium trichloride reduced solid in an inertdiluent with an activator selected from the group consisting of acomplex of diisoamyl ether and titanium tetrachloride, and a mixture ofdiisoamyl ether and titanium tetrachloride at a temperature within therange of from -30° to 100° C for at least 30 minutes, wherein the moleratio of diisoamyl ether to titanium trichloride is at least 0.1 and theconcentration of titanium tetrachloride in the diluent is maintained atat least 1 volume percent.
 2. A process according to claim 1 wherein thealuminum compounds are removed by washing with a complexing agent.
 3. Aprocess according to claim 2 wherein the complexing agent is selectedfrom the group consisting of ethers, thioethers, thiols,organo-phosphorus compounds, organo nitrogen compounds, ketones andesters.
 4. A process according to claim 3 wherein the complexing agentis di-n-butyl ether.
 5. A process according to claim 1 wherein theactivator is a complex of diisoamyl ether and titanium tetrachloride. 6.A process according to claim 1 wherein the activator is a mixture ofdiisoamyl ether and titanium tetrachloride.
 7. A process according toclaim 1, wherein, in said contacting of violet titanium trichloridereduced solid in inert diluent with said activator, the mole ratio ofdiisoamyl ether to titanium trichloride is within the range of 0.1 to0.6, the concentration of titanium tetrachloride in the diluent is atleast 5 volume percent and the reduced solid concentration in thediluent is at least 50 grams per liter.